I say go with what works for you (and your budget). I'm pretty sure the transformation to 100's is no less as strong as changing them to a lesser denomination but I would think it's probably a stronger impact when those Benjamins appear. I performed it again yesterday in a spur of the moment and the reactions were off the hook... maybe it's "too" strong. People sort of lose control lately... perhaps it's the extreme burn handling that I've incorporated... I don't want to over-analyze it... use the denomination that floats your boat... it's just nice to use 100's because people can't ask you to "top" that which could happen if you change to a lesser denomination... Have fun and entertain!!

Perhaps Kaps was right, Blank white paper to any denomination greenbacks does indeed provide the most stark contrast, and I have done that change many times, but many of us are "restless" and just feel the burning need to "experiment", always looking for that ultimate magic high... if ya' know what I mean.

A member of the local ring, Steve Rogers, does a bill switch from a one to a five, and then asks for a twenty to change it into a hundred. Maybe you could do the same multiply by 5 with a bunch of ones. It sort of defines the "limits" of your powers.

Or maybe you can do something like do the change to a bunch of mis-made bills with the explanation that you are still working on the method.